Stacked compartment conveyor assembly for dispensing machine



July 23, 1968 LE ROY D. GORE STACKED COMPARTMENT CONVEYOR ASSEMBLY FORDISPENSING MACHINE Filed Aug. 18, 1966 4 Sheets-Sheet 1 INVENTOR Le Roy0. Gare y 23, 1963 LE ROY D. GORE 3,393,952

STACKED COMPARTMENT CONVEYOR ASSEMBLY FOR DISPENSING MACHINE Filed Aug.18, 1966 4 Sheets-Sheet 2 m l 0 @D i g I02 INVENTOR LeRoy D. Gore ATTO.N

y 23, 1968 LE ROY D. GORE 3,393,952

STACKED GOMPARTMENT CONVEYOR ASSEMBLY FOR DISPENSING MACHINE Filed Aug.18. 1966 4 Sheets-Sheet 3 23 //2 LeRoy D. Gare Mffi ATTORN July 23, 1968LE ROY D. GORE STACKED COMPARTMENT CONVEYOR ASSEMBLY FOR DISPENSINGMACHINE 4 Sheets-Sheet 4 Filed Aug. 18, 1966 HH I.

INVENTOR LeRoy D. Gore United States Patent Office 3,393,952 PatentedJuly 23, 1968 3,393,952 STACKED COMPARTMENT CONVEYOR ASSEM- BLY FORDISPENSING MACHINE Le Roy D. Gore, Independence, M0., assignor to TheVendo Company, Kansas City, Mo., a corporation of Missouri Filed Aug.18, 1966, Ser'. No. 573,349 17 Claims. (CI. 312--352) ABSTRACT OF THEDISCLOSURE A dispensing machine having a series of product receivingindividual compartments positioned in stacked relationship presentingtwo side-by-side vertical columns with mechanism being provided forraising one stack one step while lowering the other stack one step, andto effect transfer of the uppermost compartment from the stack which hasbeen raised to the top of the other stack after the latter has beenlowered and to transfer the lowermost compartment of the stack which hasbeen lowered to the bottom of the stack which has been raised. Rotatablecam structure is provided at the bottom of the stacks for simultaneouslysupporting both stacks while being operable during rotation thereof toraise the one stack and lower the other stack. The cam structure islocated in disposition such that at least a part of the gravitationalload of the stack being lowered is transferred as an upward force on thestack being raised, thus minimizing the power required to drive the camstructure. A reciprocable pusher forming a part of the mechanism isoperable in timed relationship with the cam structure to shift the uppercompartment from the stack which is raised to the stack which is loweredby the cam structure.

The instant invention relates to an improved stacked compartmentconveyor assembly of the type having special utility for use in anarticle dispensing machine and in particular, relates to improvedmechanism for supporting and moving the individual compartments of suchan assembly along a closed loop path.

Product dispensing machines and related mechanisms, such as, forexample, low profile display counters, have heretofore been providedwith conveyor mechanism for supporting a plurality of individual productcompartments disposed in a pair of side-by-side stacks thereof. In theseassemblies, products are made available for dispensing by controlledshifting of the compartments to successively bring the same intoalignment with a product delivery area. This arrangement, althoughsomewhat expensive, is desirable from a space conservation viewpoint andadditionally provides flexibility for use of the machine with a varietyof different articles including pressure deformable articles andproducts of various sizes. In machines of this type, the compartments ofone stack are generally raised, the compartments of the other stack arelowered, the lowermost compartment of the lowered stack is insertedunder the raised stack, and the uppermost compartment of the latter istransferred onto the lowered stack.

Machines having stacked compartment conveyor mechanism have generallybeen motor driven. In the past it has been considered relativelyessential that large motors be used for lifting the stack of compartmentunits particularly when the compartments are fully loaded. These largemotors have increased the manufacturing as well as operational expensesof the machines.

It is, therefore, the primary object of the instant invention to providea stacked unit, closed loop conveyor for such a machine wherein isincluded structure permitting the use of a smaller motor than hasheretofore been possible, whereby manufacture and use of the machine isless expensive.

As a corollary to the foregoing object, it is a very important aim ofthe present invention to provide an element engageable with therespective stacks for translating the gravitational force exerted by thestack being lowered into an upwardly directed force acting on the stackbeing raised, thereby permitting use of a smaller mot-or.

A very important object of the invention is to provide means forrotatably mounting such an element for rotation about an axis disposedbetween the stacks whereby the stack being raised is supported by anupwardly moving portion of the element disposed on one side of the axis,and the stack being lowered is supported by a downwardly moving portionof the element disposed on the other side of the axis and the elementmounting means provides a fulcrum for translating the gravitationalforce exerted on the downwardly moving portion by the descending stackinto an upwardly directed force exerted on the ascending stack throughthe upwardly moving portion of the element.

Another very important object of the instant invention is the provisionof novel support and release means for said stacks including a movableelement having a surface engageable with the stacks for supporting thesame while the lowermost compartment of the lowered stack is releasedfor gravitation and transfer of the same beneath the ascending stack anda sec-0nd surface disposed for shifting the released unit laterally andupwardly toward the ascending stack upon further movement of theelement, to the end that the individual units of the stacks areefficiently lowered, transferred and raised by use of novel conveyorapparatus requiring a minimum number of individual components andseparate operations.

A further important object of the present invention is to providemechanism for operating the conveyor including a releasable latchdisposed for engaging the descending stack .and a pair of cam elementsmounted on opposite sides of the stacks for rotation about an axiextending between the stacks and having continuous cam tracks includingan arcuate surface movable into stacksupporting disposition duringrelease of the lowermost unit and a flat surface for transferring thereleased unit and then simultaneously raising and lowering therespective stacks, whereby the gravitational force exerted on theelement by the descending stack is translated into a force for raisingthe ascending stack and production of the conveyor assembly iseconomically and speedily carried out because the same consists of aminimum number of readily synchronized components.

Another important object of the invention is the provision of stationarycam structure disposed beneath the descending stack so that, afterrelease of the lowermost unit of the lowered stack, the same willgravitate against the cam structure and be shifted thereby into thesweep of the rotatable cam element.

Pilfering of products from coin'operated vending machines is a problemwhich must be considered in constructing such machines. Therefore, it isa very important aim of the instant invention to provide pusherstructure for transferring the uppermost tray of the raised stack ontothe lowered stack including a member for blocking an open end of thetray whereby products are vended from the top of the stacks forconservation of headspace and yet access to trays in the other stack isprecluded.

In its broadest sense, the purpose of the present invention is toprovide a practical and dependable stacked unit conveyor apparatuscomprising a minimum number of individual components and requiringminimal power for operation so that construction and operationalexpenses are lower than has been possible in the past.

Other objects and advantages of the present invention will becomeapparent from the following specification and accompanying drawings,wherein:

FIGURE 1 is a side elevational view, partially in crosssection withcertain parts being broken away for increased clarity, illustrating thestandby position of a stacked unit conveyor mechanism embodying theconcepts and principles of the instant invention;

FIG. 2 is an enlarged, fragmentary, side elevational view of themechanism shown in FIG. 1 with the sidewall removed;

FIG. 3 is an enlarged, fragmentary view similar to FIG. 2, showing themechanism after having been moved through a portion of the cycle ofoperation;

FIG. 4 is an enlarged, fragmentary, side elevational view, similar toFIGS. 2 and 3, with the mechanism at still another position during itscycle of operation;

FIG. 5 is an enlarged, cross-sectional, elevational view taken alongline 55 of FIG. 1;

FIG. 6 is an enlarged, cross-sectional, elevational view taken alongline 6 6 of FIG. 1;

FIG. 7 is an enlarged, cross-sectional plan view taken along line 7-7 ofFIG. 1;

FIG. 8 is a cross-sectional, detail plan view taken along line -88 ofFIG. 1; and

FIG. 9 is an enlarged, cross-sectional elevational view of one end of anindividual compartment.

The numeral 10 denotes a stacked compartment conveyor apparatusembodying the principles and concepts of the instant invention.Apparatus 10 includes a plurality of individual units 12 in the natureof a product cornpartment or tray. Each compartment 12, as best shown inFIG. 5, is transversely C-shaped and has a bottom wall 14, a pair ofopposed, vertical sidewall 16, and a horizontal flange 18 extendinginwardly from the uppermost extremity of each wall 16. The right andleft ends of each compartment 12, viewing FIG. 1, are open, and anannular flange 20 extending outwardly from each wall 16 mounts anannular cam follower 22 of resilient plastic material such as Teflon orthe like.

Trays 12, as described herein, are suitable for use withirregularly-shaped articles such as, for example, ice cream bars orpackages of nuts, or with pressure deformable articles such asexemplified by pieces of pie or sandwiches since, as can be seen in FIG.1, the bottom wall 14 of compartment 12 rests on the flanges 18 of thenext lower compartment 12 and is supported thereby. It is to beunderstood that the specific form chosen for unit 12 is not critical,and it will be apparent to those skilled in the art that other types oftrays, compartments or units may be used without deviating from theinventive concepts described herein. In this respect, it is to be notedthat so long as units 12 are capable of supporting one another in ahorizontal stack, they will serve the purposes of the instant invention.

Apparatus 10 has a bottom wall 23, a pair of opposed sidewalls 24 and26, and a central wall 28 extending laterally therebetween. An inwardlydirected lip 30 extends around the periphery of each wall 24 and 26, ascan best be seen viewing FIGS. 6 and 7. Compartments 12 of apparatus 10are maintained in a pair of separate, upright, side by-side stacks 32and 34 by the engagement of wall 28 and one end of compartment 12, andby the engagement between lip 30 and followers 22 as can be seen in FIG.1.

It is to be noted that the individual compartments 12 in each stack 32and 34 are supported by the other compartments 12 therebelow, and arevertically shiftable within the confines presented by wall 28 and lips30. Thus, walls 23, 24, 26 and 28, and lips 30 present guide means formaintaining the individual compartments 12 within a horizontal, closedloop path of travel. A slot 36 is provided in lip 30 at the upperleft-hand corner of walls 24 and 26 for removal and insertion ofindividual trays.

Apparatus 10 includes mechanism broadly designated by the numeral 38 forraising stack 32 on step, lowering stack 34 one step, transferring theuppermost unit 12 of stack 32 onto stack 34 after stack 32 has beenraised one step, and transferring the lowermost unit 12 of stack 34underneath stack 32 after stack 34 has been lowered one step. Mechanism38 includes drive means 40 having a motor-driven pinion 42 formotivating an endless chain 44. Chain 44 is looped around a drivenpinion 46 rotatable with a shaft 48 extending laterally between walls 24and 26 at the lower ends thereof. Driven pinion 46 is shown only inFIGS. 5 and 7 and has been deleted from the other figures for increasedclarity. However, it is to 'be understood that whenever drive means 40is actuated, pinion 46, and thereby shaft 48, will be rotated about anaxis between stacks 32 and 34.

A reciprocable pusher 50 is disposed at the upper end of apparatus 10for transferring successive uppermost compartments 12 of stack 32 ontostack 34. Pusher 50 is mounted between a pair of elongated arms 52, eachof the latter extending upwardly adjacent the outer side of a respectivewall 24 or 26, and being actuated by a respective cam 54 rotatable withshaft 48 at opposite ends of the latter. The arms 52 and earns 54 onopposite sides of apparatus 10 are substantially mirror images and,therefore, only those on one side, as shown in FIG. 1, will be describedin detail. Arm 52 is pivotally mounted on apparatus 10 by means 56 forswinging about a horizontal axis. Arm 52 includes a substantiallytriangularly-shaped plate 58 at the lower end thereof having a pair ofopposed shoulders 60 and 62 extending laterially and outwardlytherefrom. Cam 54 has a finger 64 engageable with shoulders 60 and 62respectively, as cam 54 is rotated with shaft 48 for shifting plate 58to the right and then to the left. Shaft 48 is received within anarcuate slot 66 in plate 58, permitting the latter to reciprocate asfinger 64 sequentially engages shoulders 60 and 62 during the rotationof shaft 48.

Means for releasing individual lowermost compartments 12 of stack 34 forgravitation from the latter in the nature of a releasable latch 68, ispivotally mounted on apparatus 10 for rotation about a horizontal axis.Latch 68 has a shoulder 70 thereon disposed for engaging the lowerright-hand corner of the lowermost compartment 12 in stack 34. Latch 68is urged in a clockwise direction, viewing FIG. 1, by yieldable means 72and into a position with shoulder 70 underlying stack 34. Means forselectively moving latch 68 in the nature of a bar 74 is pivotallymounted on latch 68 as can be seen in FIG. 1, and extends therefromtoward shaft 48. An elongated slot 76 in bar 74 extends longitudinallyof the latter and receives shaft 48 therethrough. Slot 76 is disposed topermit bar 74 to reciprocate along its length relative to shaft 48.Triangular plate 58 has a corner 78 disposed for engaging a tab 80extending laterally from bar 74. Thus, as plate 58 and arm 52 are movedin a clockwise direction around pivot means 56 by the interactionbetween finger 64 and shoulder 60, corner 78 engages tab 80 to move bar74 rightwardly and thus swing latch 68 in a counterclockwise directionto move shoulder 70 from beneath the lowermost unit 12 of stack 34.

Viewing FIG. 2, means in the nature of an inclined ramp 82 is disposedwithin the path of travel of an uppermost compartment 12 as the latteris transferred from stack 32 onto stack 34 by pusher 50. Ramp 82 isinclined upwardly and away from stack 32, thus elevating the leadingedge of the uppermost compartment 12 being transferred by pusher 50 forraising the same into clearing relationship with respect to stack 34. Asmentioned previously, the right-hand and left-hand ends of eachcompartment 12 are open, This construction is desirable for facilitatingloading of the apparatus with products to be dispensed and removal ofthe same during the dispensing operation. Pusher 50, as can be seen inFIG. 6, includes means in the nature of a gate 84, for closing theproximal end of the tray being shifted thereby during the transferringoperation and thereafter, during standby in the position shown inFIG. 1. As mentioned previously, apparatus is preferably utilized in amanner to conserve headroom and the dispensing operation is, therefore,conducted by providing access to the uppermost compartment of stack 34immediately after transfer of the latter from stack 32 and whileapparatus 10 is in its standby position. Thus, gate 84 is disposed toprevent access to the uppermost compartment of stack 32 to precludepilfering of articles therefrom.

It is to be noted that each compartment 12 has a pair of openings 86 ineach wall 16 thereof. A corresponding opening 88 is provided in wall 24,permitting an unrestricted view along the dashed line 90 shown in FIG. 8across compartment 12. Electric eye means 92 are disposed for directingand sensing a beam of light traveling along path 90, and it can be seenthat an article disposed within compartment 12 would block path 90.Thus, electrical signals emitted by electric eye means 92 may be usedfor controlling the operation of apparatus 10 in a manner well known tothose skilled in the art.

Support means 94, pivotally mounted on apparatus 10 for rotation about ahorizontal axis as illustrated in FIG. 2, has a ledge 96 and an inclinedsurface 98 extending transversely across apparatus 10 at the lower endof stack 32. A spring 100 is provide-d for yieldably biasing means 94into a position with ledge 96 underlying the lower lefthand corner ofthe lowermost compartment 12 in stack 32.

Means within the path of gravitation of a compartment 12 released bylatch 68 in the nature of a pair of triangular plates 102, is providedfor engaging a gravitating compartment 12 and shifting the same towardstack 32. Plates 102 are disposed on opposite sides of stack 34 adjacentthe inner side of walls 24 and 26, respectively, and have surfaces 104inclined downwardly toward stack 32 and positioned for engaging thefollowers 22 on opposite sides of the released compartment 12. Aninclined ramp 106 extends upwardly and leftwardly at the left-hand sideof bottom wall 23 for a purpose to be described hereinafter.

Central wall 28 terminates at its lower end in spaced relationship withrespect to bottom wall 23 and adjacent shaft 48. The lower portion 108of central wall is narrower than the remainder of the wall 28 defining aspace 110 between portion 138 and respective sidewalls 24 and 27. Arespective cam element 112 is mounted on each end of shaft 48 forrotation therewith adjacent the inner side of a respective wall 24 or 26through spaces 110. Cam elements 112 on each end of shaft 48 aresubstantially identical-hence only one of the same need be described indetail.

Element 112 has a continuous cam track 114 on the outer peripherythereof including an arcuate surface 116 concentric with shaft 48 and afiat surface 118. In the configuration illustrated in FIG. 4, surface118 has a portion 120 on the left-hand side of shaft 48, and a portion122 on the right'hand side of shaft 43. Drive means 40 is operablyconnected with pinion 46 for driving shaft 48 and thereby element 112,in a clockwise direction viewing FIG. 4, and thus, during rotation ofelement 112 portion 120 is disposed for upward movement, while portion122 thereof is disposed for downward movement. It is to be understoodthat the respective elements 112 on each end of shaft 48 cooperate withthe latter to present structure for engaging followers 22 on each sideof stacks 32 and 34.

Operation As mentioned above, FIG. 1, along with FIGS. 2, 5, 6 and 7,illustrate the apparatus in its standby position. Viewing FIG. 2, it canbe seen that a compartment 12 has been previously released by latchmeans 68 and has gravitated into a position underlying stacks 32 and 34on bottom wall 23. It is to be noted that surface 116 of element 112 isin engagement with follower 22 of the lowermost compartment 12 of stack34 and thereby supports stack 34. Likewise, followers 22 of thelowermost compartment 12 of stack 32 engage surface 116 and aresupported thereby. As elements 112 are rotated in a clockwise direction,portion will move into a position engaging the followers 22 ofcompartment 12 resting on wall 23. At approximately the same time,surface 116 will have been rotated beyond the followers 22 ofcompartment 12 at the lower end of stack 32, permitting stack 32 togravitate onto and be supported by ledge 96 of support means 24. In themeantime, upon rotation of shaft 48, finger 64 of cam 54 has beenrotated out of engagement with shoulder 66 and into engagement withshoulder 62, thus urging pusher means 50 leftwardly. This action of cam54 also results in withdrawing corner 78 from engagement with tab 80,permitting spring means 72 to bias latch 68 into a position withshoulder 70 underlying stack 34.

Upon further clockwise rotation of element 112, compartrnent 12 lying onwall 23 is swept laterally toward stack 32 by portion 120 of element 112and upon contacting ramp 166, the compartment being transferred byportion 120 is elevated slightly, permitting portion 120 to moveslightly beneath the follower 22 thereon, thus sweeping the compartment12 being transferred upwardly toward stack 32. This action is bestillustrated in FIG. 3, and it can be seen therein that the compartment12 being swept upwardly will contact surface 98, forcing support menas94 against the bias of spring 100, thus permitting passage of thecompartment 12 being swept upwardly, toward stack 32. Upon continuedmovement of element 112 in a clockwise direction, it can be seen,viewing FIG. 4, that the compartments 12 in stack 32 will be movedupwardly by portion 120 of surface 118. Likewise, in the meantime,surface 116 has rotated beyond followers 22 on the lowermost compartment12 of stack 34. Thus, stack 34 is permitted to move downwardly incontact with portion 122 of surface 118. It can be seen, viewing FIG. 4,that the gravitational load G exerted downwardly on portion 122 by stack34 during the downward movement of the stack, is translated about thefulcrum provided by shaft 48 into an upwardly directed force F actingthrough portion 120 onto the upwardly moving stack 32. Thus, thedownward movement of stack 34 assists drive means 40 in raising stack32.

Again viewing FIG. 4, upon continued clockwise rotation of element 112,stack 34 will be lowered into a position with the lowermost compartment12 therein occupying the position designated by dashed lines and stack34 is supported by shoulder 70 of latch 68. Also, at this point, thelowermost compartment 12 of stack 32 will have been moved upwardlybeyond ledge 96, permitting support means 94 to move underneath stack 32under the influence of spring 1112. Continued clockwise rotation ofelement 112 will move surface 116 into a position underlying thefollowers 22 of the next to lowermost compartment designated 12a instack 34.

During the movement of surface 116 into a position underlying thefollower 22 of compartment 12a, cam 54 has rotated away from shoulder 62and back into contact with shoulder 62, thereby urging pusher 5'0 andtriangular plate 58 rightwardly, thus moving the uppermost compartmentof stack 32 occupying the position shown by dashed lines in FIG. 4,rightwardly over ramp 82 and onto stack 34. As pusher 5% reaches the endof its path of travel in blocking relationship to the open end of thetransferred compartment 12, now at the uppermost end of stack 34, corner78 engages tab 81}, swinging latch means 68 and shoulder 711 into aclearing position with respect to the lowermost compartment 12 of stack34, then releasing the latter for gravitation. It is to be remembered atthis point that element 112 has reassumed the position in FIG. 2;therefore, stack 34 is supported by surface 116 while the lowermostcompartment gravitates therefrom.

During gravitation of the released compartment 12, the followers 22thereof engage surfaces 104 of plates 102, and the released compartmentis shifted by inclined surfaces 104 toward stack 32 and into the path ofportion 120 as the latter is rotated.

Thus, it can be seen that the motor required for raising stack 32 may beof minimal size because of the counterbalancing or teeter-totter effectof surface 118. Additionally, all of the other objects, aims andpurposes of the instant invention have been fulfilled in a substantialsense. It is of particular note that all of the component of apparatus10 are operated from the single drive shaft 48 and thus, a high degreeof compactness has been achieved. Furthermore, all of the various stepsof apparatus 10 are caused to occur by positive actuation under theinfluence of cams 54 and elements 112 rotating on a common shaft 48 and,therefore, a high degree of synchronization has been achieved with aminimum number of relatively movable components.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. In a machine having a pair of separate stacks of individual,vertically shiftable rectangular units and mechanism for raising one ofthe stacks one step, lowering the other stack one step, transferring theuppermost unit of said one stack onto said other stack after the onestack has been raised one step and transferring the lowermost unit ofsaid other stack underneath said one stack after said other stack hasbeen lowered one step, said mechanism including:

movable structure engageable with the lowermost units of the stacks forsimultaneously supporting both stacks during raising of said one andlowering of said other stack,

said structure being movable during stack raising and lowering operationabout an axis disposed to translate the gravitational load of said otherstack into an upwardly directed force acting on said one stack.

2. The invention of claim 1,

said structure including an element having a stack supporting surface,

said element being rotatable about said axis,

said surface being disposed relative to said axis for upward movement ofone portion thereof on one side of the axis and downward movement ofanother portion thereof on the other side of said axis during saidoperation,

said one portion supporting the one stack and said other portionsupporting the other stack during said operation.

3. The invention of claim 2,

said element having a second surface movable after said operation andduring continued rotation of said element, to a position supporting saidother stack during said transfer of the lowermost unit of said otherstack. 4. In a machine having a pair of separate stacks of individual,vertically shiftable units and mechanism for raising one of the stacksone step, lowering the other stack one step, transferring the uppermostunit of said one stack onto said other stack after the one stack hasbeen raised one step and transferring the lowermost unit of said otherstack underneath said one stack after said other stack has been loweredone step, said mechanism including and means within the path of travelof the tray being transferred by the pusher for raising the same intoclearing relationship to said other stack upon which it is deposited bythe pusher.

6. In a machine having a pair of separate stacks of individual,vertically shiftable units and mechanism for raising one of the stacksone step, lowering the other stack one step, transferring the uppermostunit of said one stack onto said other stack after the one stack hasbeen raised one step and transferring the lowermost unit of said otherstack underneath said one stack after said other stack has been loweredone step, said mechanism including:

means for releasing said lowermost unit of said other stack forgravitation therefrom only after said other stack has been lowered onestep; and

cam structure engageable with the released unit for moving the latterlaterally and thence upwardly into engagement with the lowermost unit ofsaid one stack.

7. The invention of claim 6,

and means within the path of gravitation of the released unit foreffecting lateral movement thereof prior to its continued lateralmovement by said structure.

8. The invention of claim 6,

said structure having a unit engaging surface disposed to sweep thereleased unit laterally and upwardly; and

means within the path of gravitation of the released unit for shiftingthe same during gravitation into the path of travel of said surface.

9. The invention of claim 6,

said structure including an element having a first surface movable to aposition supporting said other stack prior to release and transfer ofsaid lowermost unit and a second surface disposed to sweep the releasedunit laterally and upwardly.

10. In a machine having a pair of separate stacks of individual,vertically shiftable units and mechanism for raising one of the stacksone step, lowering the other stack one step, transferring the uppermostunit of said one stack onto said other stack after the one stack hasbeen raised One step and transferring the lowermost unit of said otherstack underneath said one stack after said other stack has been loweredone step, said mechanism including:

a releasable latch disposed for engaging the lowermost unit of saidother stack after the latter has been lowered one step for supportingsaid other stack;

means for selectively moving said latch to a position clearing saidother stack after the latter has been lowered one step thereby releasingsaid lowermost unit of the other stack for gravitation therefrom; and

structure including an element rotatable about an axis between saidstacks and having a first surface movable during rotation of the elementto a position supporting said other stack prior to releas and transferof the lowermost unit of said other stack and a second surface havingone portion disposed to sweep the released unit laterally and upwardlytoward said one stack upon continued rotation of said element,

said one portion being movable during further rotation of said elementto a position supporting said one stack,

said second surface having another portion disposed for supporting saidother stack while the one portion is supporting the one stack,

said second surface being disposed relative to said axis for upwardmovement of said one portion on one side of said axis and downwardmovement of said another portion on the other side of said axis uponcontinued rotation of the element, whereby said one stack is raised onestep and said other stack is simultaneously lowered one step.

11. The invention of claim 10,

said first surface being arcuate and substantially concentric with saidaxis, said second surface being substantially fiat, said surfaces beinginterconnected and presenting a continuous cam track.

12. The invention of claim 11,

each of said units including a tray having a bottom wall and a pair ofside walls, there being a cam follower extending laterally from eachside wall,

said structure including an elongated shaft rotatable about said axis,there being one of said elements at each end thereof,

said lowermost trays being disposed between said elements with thefollowers thereof normally engaging said track.

13. The invention of claim 10,

a pusher reciprocable at the upper end of said one stack, transverselythereof for transferring successive uppermost units of the one stackonto the other stack; and

mechanism operably coupled with the pusher, the

means for selectively moving the latch and said structure for operatingthe same in sequential synchronization.

14. The invention of claim 12,

and means below said other stack having a pair of spaced surfacesinclined downwardly toward the one stack and disposed for engaging thefollowers of the released tray to thereby shift the follower of thereleased tray during gravitation of the latter into the path of travelof said one portion.

15. The invention of claim 12,

and guide means including a pair of spaced-apart walls on opposite sidesof said stacks for maintaining said trays in said stacks,

each wall having inturned flange means disposed for engagement with saidfollowers throughout the upward and downward movement of each tray.

16. The invention of claim 15,

and a floor between said walls beneath said stacks, said floor and saidflanges defining a closed loop path of travel for upward and downwardmovement and transfer of said trays.

17. In a machine having a pair of separate stacks of individual,vertical shiftable rectangular units and mechanism for shifting theupper unit of one stack onto the top of the other stack in conjunctionwith transfer of the lower unit of said other stack to the bottom ofsaid one stack, the combination with said mechanism of structure forraising said one stack while lowering the other stack comprising:

a device engageable with the lowermost units of the stacks forsimultaneously supporting both stacks while raising said one andlowering said other stack;

means supporting said device for rotation about an axis to effecttranslation of the gravitational load of said other stack into anupwardly directed force acting on said one stack; and

drive means connected to said device for rotating the latter.

References Cited UNITED STATES PATENTS 2,315,790 4/1943 Hallwood 312-1342,888,166 5/1959 Gabrielsen 22181 3,300,086 1/1967 Wood 22167 FOREIGNPATENTS 119,027 9/1958 U.S.S.R.

OTHER REFERENCES German printed application 1,109,926, June 1961.

JAMES T. MCCALL, Primary Examiner.

